Glucagon Results Timeline: What Studies Measured, and When

What a "results timeline" means in published research

In clinical research, a timeline is not a promise about when an individual changes. It is a schedule of measurement: the week or month at which investigators collected a blood sample, a biopsy, a questionnaire or a body-weight reading, and compared groups. A trial that reported a histologic endpoint at week 48 did not establish that anything happened at week 48 in particular; it established when the measurement was taken. This page sets out those measurement windows for glucagon-receptor pharmacology and for the closely related metabolic peptide trials that define the current endpoint calendar.

Two different things are called "glucagon"

Glucagon is an endogenous 29-amino-acid pancreatic hormone, and glucagon products are approved in the United States for the emergency treatment of severe hypoglycaemia and as a diagnostic aid in gastrointestinal imaging. That regulatory use is separate from the second research context in which the glucagon receptor appears: multi-receptor agonist peptides designed to engage the glucagon receptor alongside GLP-1 or GIP receptors, which are studied over months in metabolic and liver disease.

The verified literature set used on this page contains no pharmacokinetic or pharmacodynamic study of native glucagon, so no onset time, duration of action or dose for emergency or diagnostic glucagon is stated here. Where human glucagon-specific data is absent, this page says so rather than substituting data from a different molecule.

The closest human timeline: a 48-week dual-agonist trial

Survodutide is a glucagon-receptor and GLP-1 receptor dual agonist, and the phase 2 trial published in 2024 enrolled adults with biopsy-confirmed metabolic dysfunction-associated steatohepatitis (MASH) and fibrosis, randomly assigning them to weekly subcutaneous survodutide at 2.4 mg, 4.8 mg or 6.0 mg or to placebo (PMID 38847460). The design used an initial dose-escalation period followed by maintenance dosing, with the primary histologic endpoint — improvement in MASH without worsening of fibrosis — assessed on liver biopsy at week 48 (PMID 38847460).

Researchers reported that histologic improvement at week 48 occurred more frequently in each survodutide group than in the placebo group, with the trial also examining fibrosis and liver-fat measures over the same 48-week window (PMID 38847460). Because this was a phase 2 trial with a biopsy endpoint at a single late timepoint, the study did not characterise what, if anything, was measurable at four, eight or twelve weeks.

What that design implies about reading timelines

Two features of the survodutide trial recur across this literature. First, dose escalation consumes a substantial share of the trial before maintenance exposure begins, so early weeks are not a steady-state observation period (PMID 38847460). Second, the endpoint chosen dictates the calendar: histology requires a repeat biopsy and is therefore read at a year or near it, while a laboratory value can be read far sooner.

Measurement windows across related metabolic peptide trials

Glucagon-receptor agonism is studied inside a field whose endpoint schedule was largely set by incretin trials. The table below lists what each cited trial measured and when. None of these trials studied glucagon alone, and they are included to show the measurement calendar rather than to describe glucagon's effects.

Weeks 0–20: escalation and short-horizon questions

The shortest cited human trial ran nine weeks, in which researchers studied once-weekly semaglutide at low doses in adults with alcohol use disorder and measured alcohol-related outcomes at the end of that period (PMID 39937469). Longer trials typically treat this early span as titration: the STEP 4 trial used a 20-week run-in on semaglutide before randomising participants to continue the drug or switch to placebo (PMID 33755728).

Weeks 40–72: the main endpoint window

Glycaemic endpoints were read earliest among the long trials, with SURPASS-5 reporting HbA1c change at week 40 in participants whose tirzepatide 5, 10 or 15 mg was added to titrated insulin glargine (PMID 35133415). Liver histology endpoints were read at week 48 for survodutide (PMID 38847460), at week 52 for tirzepatide in MASH with fibrosis (PMID 38856224), and at week 72 in the phase 3 semaglutide MASH trial (PMID 40305708). Weight-centred trials clustered at week 68, including oral semaglutide 50 mg daily (PMID 37385278), once-weekly semaglutide 2.4 mg in adolescents (PMID 36322838), and the head-to-head comparison of weekly semaglutide 2.4 mg with daily liraglutide 3.0 mg (PMID 35015037).

Beyond one year: event-driven follow-up

Clinical-event endpoints cannot be scheduled the way a laboratory draw can. The cardiovascular outcomes trial of semaglutide 2.4 mg weekly in adults with obesity and cardiovascular disease but without diabetes followed participants for a mean of roughly 40 months before reporting major adverse cardiovascular events (PMID 37952131). The tirzepatide trial in heart failure with preserved ejection fraction and obesity followed participants for a median of about 104 weeks while measuring heart-failure events and health-status scores (PMID 39555826).

What is not established for glucagon in this evidence set

• No trial here studied native glucagon as a standalone agent over weeks or months, so no timeline for glucagon monotherapy is reported on this page.
• No animal or in-vitro glucagon study appears in the verified citation set; where this page describes mechanisms, it does so without attributing an effect size or a timepoint to unlisted preclinical work.
• The only glucagon-receptor-targeting human evidence cited is phase 2 and histology-based at week 48, which the study itself framed as a dose-ranging evaluation rather than a definitive outcome trial (PMID 38847460).
• Trial populations were specific — biopsy-confirmed MASH, adolescents with obesity, adults with knee osteoarthritis — and results reported in one population were not measured in another (PMID 36322838, PMID 39476339).

Adverse Events in Glucagon-Receptor Agonist Trials: What Studies Report

In the survodutide phase 2 trial, researchers reported that gastrointestinal adverse events, including nausea, vomiting and diarrhoea, were more common with survodutide than with placebo across the 48-week trial (PMID 38847460). Comparable gastrointestinal adverse-event patterns were reported in the tirzepatide MASH trial over 52 weeks (PMID 38856224) and in trials of once-weekly semaglutide 2.4 mg followed to week 68 (PMID 35015037). Adverse events in these trials were counted across the whole exposure period rather than assigned to a single week, so a tolerability timeline cannot be reconstructed from the published summaries alone.

Why two trials of the same class report different timelines

1. Endpoint type. HbA1c was read at week 40 in a type 2 diabetes trial (PMID 35133415), while biopsy-confirmed histology required 48 to 72 weeks (PMID 38847460, PMID 40305708).
2. Design. A withdrawal design measures something different from a parallel design, as in the trial that randomised participants after a 20-week run-in and then followed both groups to week 68 (PMID 33755728).
3. Event accrual. Outcome trials end when enough events have occurred, which is why follow-up was reported as a mean of about 40 months rather than a fixed visit (PMID 37952131).
4. Population. Adolescents, adults with knee osteoarthritis and adults with heart failure were assessed with different instruments on different schedules (PMID 36322838, PMID 39476339, PMID 39555826).

Educational disclaimer

This page is for educational purposes only and is not medical advice; consult a licensed physician about any medical condition, medication or treatment decision. Nothing here describes a protocol, and the group-level findings summarised above — including those reported at week 48 in the survodutide trial (PMID 38847460) — were averages across enrolled and monitored participants, not predictions for any individual.

References

• A Phase 2 Randomized Trial of Survodutide in MASH and Fibrosis (The New England Journal of Medicine, 2024)
• Tirzepatide for Metabolic Dysfunction-Associated Steatohepatitis with Liver Fibrosis (The New England Journal of Medicine, 2024)
• Phase 3 Trial of Semaglutide in Metabolic Dysfunction-Associated Steatohepatitis (The New England Journal of Medicine, 2025)
• Effect of Subcutaneous Tirzepatide vs Placebo Added to Titrated Insulin Glargine on Glycemic Control in Patients With Type 2 Diabetes: The SURPASS-5 Randomized Clinical Trial (JAMA, 2022)
• Effect of Continued Weekly Subcutaneous Semaglutide vs Placebo on Weight Loss Maintenance in Adults With Overweight or Obesity: The STEP 4 Randomized Clinical Trial (JAMA, 2021)
• Oral semaglutide 50 mg taken once per day in adults with overweight or obesity (OASIS 1): a randomised, double-blind, placebo-controlled, phase 3 trial (Lancet, 2023)
• Once-Weekly Semaglutide in Adolescents with Obesity (The New England Journal of Medicine, 2022)
• Once-Weekly Semaglutide in Persons with Obesity and Knee Osteoarthritis (The New England Journal of Medicine, 2024)
• Effect of Weekly Subcutaneous Semaglutide vs Daily Liraglutide on Body Weight in Adults With Overweight or Obesity Without Diabetes: The STEP 8 Randomized Clinical Trial (JAMA, 2022)
• Once-Weekly Semaglutide in Adults With Alcohol Use Disorder: A Randomized Clinical Trial (JAMA Psychiatry, 2025)
• Semaglutide and Cardiovascular Outcomes in Obesity without Diabetes (The New England Journal of Medicine, 2023)
• Tirzepatide for Heart Failure with Preserved Ejection Fraction and Obesity (The New England Journal of Medicine, 2025)